CCNA – Semester1
Module 1
Introduction to Networking
Objectives
•
Network physical connection
• Basic computer components
• Network math and IP address concept
Connecting to the Internet
Requirements for Internet Connection
• Connection to the Internet can be broken down into the
following:
– Physical connection: used to transfer signals between PCs within the
local network and to remote devices on the Internet
– Logical connection: uses standards called protocols. A protocol is a
formal description of a set of rules and conventions that govern how
devices on a network communicate.
– The application: interprets the data and displays the information in an
understandable form
Information flow
Case Study: Boot process
BIOS
OS
SHELL
User Interface
ROM RAM
HDD RAM
RAM IO
Network Interface Cards
• When you select a network
card, consider the following

such as Digital Subscriber Line (DSL) and cable modem
access, moved to the consumer market.
• These services no longer required expensive equipment
or a second phone line. These are "always on" services
that provide instant access and do not require a
connection to be established for each session.
TCP/IP Description and Configuration
• Transmission Control
Protocol/Internet Protocol (TCP/IP)
is a set of protocols or rules
developed to allow cooperating
computers to share resources
across a network.
• To enable TCP/IP on the
workstation, it must be configured
using the operating system tools.
Testing Connectivity with Ping
• Ping is a program that is useful for verifying a
successful TCP/IP installation.
• It works by sending multiple packets to a
specified destination requesting for replies.
Ping Command
• ping 127.0.0.1 - This ping is unique and is called an internal
loopback test. It verifies the operation of the TCP/IP stack and NIC
transmit/receive function.
• ping IP address - A ping to a host PC verifies the TCP/IP address
configuration for the local host and connectivity to the host.
Web Browser and Plug-Ins
• Web browsers acts on behalf
of a user by

• Binary numbers
– Use principle of place value just as decimal numbers do
ASCII
• The American Standard Code for Information Interchange (ASCII) is the
most commonly used code for representing alpha-numeric data in a
computer.
1000011
1001001
1010000
1010100
?
Bits and Bytes
• Bits are binary digits. They are either 0s or 1s. In a computer, they are
represented by On/Off switches or the presence or absence of electrical
charges, light pulses, or radio waves.
Base 10 Numbers
Example
Base 2 (Binary) Numbers
Converting Decimal to Binary
2
7
2
6
2
5
2
4
2
3
2

right most bit of the mask.
SubnetMask Example
• Converting the IP address 10.34.23.134 to binary
would result in:
00001010.00100010.00010111.10000110
• Performing a Boolean AND of the IP address
10.34.23.134 and the subnet mask 255.240.0.0
produces the network address of this host:
00001010.00100010.00010111.10000110 Æ 10.34.23.134 (IP address)
11111111.11110000.00000000.00000000
Æ 255.240.0.0 (subnetmask)
00001010.00100000.00000000.00000000 Æ 10.32.0.0 (subnetwork address)
Address Example
• IP address 10.34.23.134
• Subnetmask 255.0.0.0
• IP address:
00001010.00100010.00010111.10000110 = 10.34.23.134
• Network address:
00001010.00000000.00000000.00000000 = 10.0.0.0
• Broadcast address:
00001010.11111111. 11111111. 11111111=10.255.255.255
View computer address
• ipconfig : brief IP configuration
• ipconfig /all : detail IP configuration
• ipconfig /renew : renew IP address with DHCP
• Practise IP and subnetmask
Summary
• The physical connection that has to take place for a
computer to connect to the Internet
• Network interface cards and/or modems

Network Topology
• The physical topology, which is the actual
layout of the wire or media.
• The logical topology, which defines how the
media is accessed by the hosts for sending
data.
Physical Topology
Logical Topology
Broadcast
Token Passing
Logical Topology: Broadcast
• Each host sends its data to all other hosts on
the network medium.
• First-come, first-serve.
• Eg: Ethernet
Logical Topology: Token Passing
• Access to media is controlled by an electronic
token.
• Possession of the token gives the host the right to
pass data to its destination.
• Eg: Token-Ring, FDDI
Network Protocols
• Protocol suites are collections of protocols
that enable network communication from one
host through the network to another host.
• A protocol is a formal description of a set of
rules and conventions that govern a particular
aspect of how devices on a network
communicate.
Functions of Protocols

– Synchronous Optical Network (SONET)
Metropolitan-Area Networks (MANs)
• A MAN is a
network that spans
a metropolitan
area such as a city
or suburban area.
• A MAN usually
consists of two or
more LANs in a
common
geographic area.